This study examined the extent to which teacher ratings of student behavior via the Social, Academic, and Emotional Behavior Risk Screener (SAEBRS) predicted academic achievement in math and reading. A secondary purpose was to compare the predictive capacity of three SAEBRS subscales corresponding to social, academic, or emotional domains of behavior. Universal screening was conducted to evaluate 1,058 elementary students’ performance in both reading and math, which were then combined to form a composite estimate of overall academic performance. Results indicated that the SAEBRS composite scale and all three subscales each individually predicted academic performance. Results further indicated that the SAEBRS Academic Behavior subscale was the best predictor of academic performance. Furthermore, the SAEBRS Social Behavior scale was found to function as a net suppressor variable, enhancing the capacity of Academic Behavior to predict academic performance via the suppression of variance irrelevant relative to academic performance. Follow-up path analyses suggested Academic Behavior also served as a mediating variable, as it partially accounted for the relationship between Social Behavior and academic performance. Implications for educators and limitations of this study are discussed.